This invention relates to a device which transfers the force of an impact to a targeted object and, more particularly, to a slide hammer which transfers the force of an impact to a targeted object.
It is known to use various combinations of chisels and hammers in order to impart a force upon a targeted object. In the automotive repair industry, it is often necessary to reshape and straighten vehicle body frames which have been damaged. Various forms of frame straightening machines are available for such purposes. However, even with the availability of such machines, it is still necessary in most cases to apply manual force to the frame in order to achieve the exact type of reshaping necessary to straighten the frame. Particularly for hard-to-reach locations on the vehicle frame, pneumatic or hydraulic machines are simply not able to be positioned in a manner to provide force against the targeted frame location. Also, for intricate reshaping of smaller frame members, machines are unsuitable. Thus, the straightening of a vehicle body frame still requires a considerable amount of manual labor.
One disadvantage of using a hammer and chisel is that the hammer and chisel have to be firmly gripped. Because metal to metal contact is made between the frame and the chisel, most of the force of the impact is transmitted back through the user""s hands and arms. This force transmitted back through the hands and arms of a person can cause great pain and discomfort, as well as to cause premature fatigue. Because the hammer has to be swung with great force, the hammer itself can become a danger, particularly in hammering out those hard-to-reach locations on the frame. These and other known hazards make the use of a chisel and hammer undesirable.
Therefore, a need exists for a device which can be safely and easily manipulated by a user for applying a desired amount of force to a targeted object. A need also exists for a hammering device which allows a user to vary the amount of force applied by the device without having to substantially change the user""s physical efforts in manipulating the device.
It is one object of this invention to provide a slide hammer device which is able to transfer the force of an impact to a specific targeted object. It is another object of this invention to provide a slide hammer device which minimizes the reaction force which is transmitted back through the user""s hands and arms. It is yet another object of this invention to provide increased safety with a hammering device. It is yet another object of this invention to provide a hammering device which has removable and varying tip configurations in order to further control the type of force applied to the targeted object. These objects and others will be explained more fully below as they apply to the slide hammer device of this invention.
In its simplest form, the slide hammer of this invention is a hammering device which allows the force of an impact to be transferred to a targeted object. The apparatus has three major components, namely, a guide sleeve, a plunger, and an impact head. The plunger is inserted within the guide sleeve. The impact head is secured within the distal end of the guide sleeve, and has a portion which protrudes from the guide sleeve distal end. The impact head is able to freely slide within a specified portion of the guide sleeve distal end. The plunger is slid within the guide sleeve and is able to make contact with the portion of the impact head slidably secured within the guide sleeve. The force of the plunger moving striking the impact head is transmitted through the impact head to a targeted object contacted by the impact head, such as a vehicle frame member. The impact head may be fitted with various types of tips. The particular tip chosen is based upon the type of force which is to be applied upon the targeted object. The exterior dimension of the plunger and the channel or opening in the guide sleeve are sized for a relatively close tolerance fit which ensures a smooth sliding movement of the plunger within the guide sleeve. The portion of the impact head secured within the guide sleeve distal end is also sized so that it maintains a relatively precise sliding movement within the guide sleeve. Optionally, various sized weights may be added to the plunger in order to increase or decrease the amount of force which is transmitted from the plunger to the impact head. A removable handle may be mounted to the guide sleeve in order to further reduce the shock of the impact which is transmitted back through the user""s hands and arms, and also to allow the device to be more easily gripped during use. Also, a removable support may be used when the device is used to apply force to an object on the ground, such as concrete or asphalt.
The use of the guide sleeve to guide the plunger greatly increases the accuracy at which a force is applied and to a targeted object. Not only can the angle at which the force is applied be better controlled, but also the magnitude of the applied force as well. The guide sleeve acts as an alignment means for directing the force at a desired angle. Since the plunger travels along this aligned path, the angle at which the force is applied to a targeted object is very accurate. With a hammer and chisel, it is much more difficult to maintain this aligned path between the chisel axis and the angle at which the hammer strikes the chisel head; therefore, the angle at which force is applied to a targeted object is more inconsistent. In terms of force magnitude, the plunger may be slid within the guide sleeve at the appropriate velocity to increase or decrease the force transmitted through the impact head. The use of the guide sleeve in conjunction with the plunger also makes the application of force safer since there is no possibility that the plunger will become disengaged from or otherwise slip away from the impact head during impact. Since the plunger may be slid within the guide sleeve as opposed to being independently lifted or carried throughout a striking motion, the user must only overcome the slight friction between the guide sleeve and the plunger to move the plunger for contact with the impact head. The plunger may be lubricated as necessary to further reduce the amount of effort required to slide the plunger within the guide sleeve. The removable weights attached to the plunger can allow one to further vary the force applied. Additionally, the guide sleeve and plunger may be made longer or shorter depending upon the application and the amount of force to be applied to the targeted object. Because the impact head may be fitted with removable tips, the slide hammer is adaptable for use in many applications.
The use of the device results in less force being transmitted back through the hands and arms of a user. When the plunger achieves the desired velocity within the guide sleeve, the user""s hand need not be gripped tightly around the proximal end of the plunger which, in turn, reduces the amount of force transmitted back through that hand. As discussed above with respect to a standard hammer and chisel, a hammer must always be tightly gripped during impact against the chisel which, in turn, results in much greater force being transmitted back through the hand. Also, since the impact head is able to slide along a specified length within the guide sleeve, the guide sleeve itself may recoil and absorb the retransmitted impact force which further reduces the shock experienced by the user""s hand which grips the guide sleeve. In general, the sliding engagement of the impact head and the plunger within the guide sleeve combines to enhance the shock absorption characteristics of the slide hammer.
Since the impact head is able to slide with minimal resistance within the specified portion of the guide sleeve, the full impact of the moving plunger may be transmitted to the impact head which, in turn, helps to ensure that an adequate force is applied to the targeted object.
In addition to the above described advantages of the slide hammer, the slide hammer also includes a number of varying tip configurations which can be used to apply force upon a targeted object. The tip configurations are designed specifically for applying force for different types of situations. Thus, the removable tips enable the slide hammer to be used as a universal means for applying force to a targeted object.
These and other advantages will become more apparent by a review of the following figures, in conjunction with the detailed description.